If the .280 British or .276 Pedersen were adopted, would we have the 5.56?

[iamkris]

Just looking at the ballistics of the 6.8 SPC and 6.5 Grendel in the AR. The ballistics look not all that dissimilar to the old .276 Pedersen (125 gr 7mm bullet at 2550 fps) that Garand originally designed his rifle for and the .280 British (140 gr 7mm bullet at 2530 fps) the 7x43 mm cartridge the British were promoting in the 50's for the NATO standard against the 7.62x51 mm (T65).

If either of these had been adopted...e.g., a more controllable in full auto round but still decently powerful...do you think we would have moved to the 5.56?

Not meaning this to be a 5.56 bashing thread (I shoot it and like it for what is)...just wondering. These were still long cartridges...but shorter than the .308. Would the length difference been enough to drive us to shorter actions and lighter weight?

 

[JShirley]

I think the downsizing process would have continued, much like the .30-06 to .308.

John

 

[Crosshair]

No, had we gone there we would not have the .223 today.

 

[belton-deer-hunter]

yep

i think if not we would either still be using the 30-06 or we would have downsized to our own calibers like mabee a 243 or even a .22 i think that it would make a good combat weapon jsut because of it's sixe i mean sure it is smaller and slower with less power but you could caryy two bricks instead of one and ammo is a big deal in combat

 

[GunnySkox]

I think we would've ended up with space-age EBR-looking guns and such (like the M16) anyway, but that we would've stuck with a proper intermediate cartridge rather than bouncing 'tween Full Power and "Poodleshooter" (as the grognards say) and trying to get back toward the Intermediate again.

"And I base this on absolutely nothing." ~Some character on South Park.

~GnSx

 

[jacobtowne]

Something to consider: In 1932 Army Ordnance had accepted Garand's first gas-operated rifle in cal. .276. The chief of staff, MacArthur, vetoed it, setting the program back four years and creating a rifle whose major fault was its weight, the M1.
It's interesting to speculate on what would have happened had someone else been chief of staff, someone who would not have insisted on .30 caliber.
Would we have shortened the round during WWII for a select fire rifle, like one version of the M1 carbine, as the Germans did for their assault rifle?
The Russians also produced a short .30 caliber cartridge, still in wide use today.
The two .28 caliber cartridges would have served for:
Assault rifle
Sniper rifle
Rifle
Machine gun
JT

 

[iamkris]

Yes, kind of my thoughts. Don't get me wrong, I really enjoy the 30-06 in my Garand and 03A3 and the 7.62 NATO in my FAL and M1A, I just think those cartridges are a nice compromise without having compromise of performance. Lighter, shorter, lower recoil with better exterior ballistics than the 7.62x39mm, better penetration, etc.

 

[BigG]

Well I can see a couple reasons why MacArthur did not change to the 276 Pedersen: 1. The army was downsized, as in peacetime; 2. changing the rifle caliber would add a new item into the supply chain; 3. when machine guns and SAWs were chambered for 30/06 making the rifle caliber incompatible does not seem like a good idea in the interest of ammo interchangeability. 4. There were multiple millions of 30/06 stockpiled; 5. It was the height of the Great Depression.

I do not think the 276 would have made much of a difference as to controllability under FA. The 223/5.56 would still have made its debut, imho.

 

[iamkris]

Logistics-wise that makes sense...same reason I suppose it's impractical to move from 5.56 now.

Re: controllability of .276 in FA, anyone ever shot this class of round in full auto? I guess you have something there...I did a little experiement with a recoil calculator

For example
5.56x45 mm in a 7 lb gun -- recoil energy is ~5 ft-lbs
7.62x39 mm in a 7 lb gun -- recoil energy is ~6 ft-lbs
.276 Pedersen in a 8 lb gun -- recoil energy is ~8 ft-lbs
.280 British in a 8 lb gun -- recoil energy is ~10 ft-lbs
7.62x51 mm in a 9 lb gun -- recoil energy is ~11 ft-lbs

 

[NMshooter]

I consider it ironic that it would have been no more difficult to have adopted the .276 as what we went through with several different calibers, particularly .30C, in the middle of WW2.

And at the time (1936) the active Army was small enough that it would not have been a big deal to switch over, with the various state organizations switching or staying with the Springfield in .30 .

The M1919 MGs could have been rebarreled, and the BAR really needed to be replaced with something lighter.

It is rather interesting how many other countries at that time were trying cartridges around 6.5mm, but ended up going back to 7.5mm or so by the beginning of the war.

I suspect our current service rifle would be the AR-10, and Stoner would have designed it around the .276 that had "won WW2" instead of the .30-06 that he really built that rifle around initially.

And we would still be arguing over whether that rifle or the older Garand it replaced was the better one...

 

[Tony Williams]

Your calcuations of recoil are very incorrect. 130 grs x 2300 fps=29.9 recoil-momentum. 60 grs at 3000 fps is 18 recoil-momentum. So the 7.62x39 has about 2/3rds more recoil than 223, if the gun's action and wt are identical.

Recoil momentum, yes, but what the shooter experiences is recoil energy, so you have to square those results.

I included an ammo table in the back of Assault Rifle: the Development of the Modern Military Rifle and its Ammunition which I wrote with Max Popenker. Comparative recoil energy factors (in weapons of identical weight and type) of some common rounds are:

5.45x39 - 24
5.56x45 M855 - 32
7.62x39 - 59
6.8x43 Rem - 71
7x43 EM-2 - 90
7x51 Pedersen - 85
7.62x51 NATO - 142

Tony Williams: Military gun and ammunition website and discussion forum

 

[iamkris]

Jumbee

Granted my bachelors and masters degrees in engineering are a little dated (haven't used them in over 15 years) but every text I can find and all the recoil calculators I find do not reference momentum as a measure of recoil. They all state recoil energy in ft lbs and also show recoil velocity to calculate energy as noted by Tony.

I have no reason to doubt you but I certainly can't find anything myself to support your view.

Would love to understand if all these folks got it wrong so I can stop quoting bad info

http://www.beartoothbullets.com/rescources/calculators/php/recoil.htm
http://www.handloads.com/calc/recoil.asp
http://www.huntamerica.com/recoil_calculator/
http://www.rfgc.org/reload/recoil_calc.htm

 

[iamkris]

No, I'm trying to find an honest calculation of recoil energy. You are quoting a mix of momentum and power factor, neither of which are measures of actual recoil energy.

A 230 gr .45 military load, at 850 fps, thus has a recoil-factor of 195

That's power factor, not recoil energy. I've never heard of recoil-factor.

Just trying to get the facts straight. Your request of placing a buttstock on one's nose is colorful but it doesn't get an actual calculation of energy.

 

[jaimeshawn]

For a formula for recoil, I would guess you could look at pressure times the area of the base of the bullet – for if the bullet is being pushed forward with a specific force, then the gun and shooter have to be pushed back with the same force – equal and opposite and all that – I’ll leave it to you engineers to figure that out.

Personally, my calibrated shoulder says .223 recoil is nearly nothing. 7.62x39 recoil feels about twice that, and I start my grandkids off shooting that caliber, since it is so mild. My youngest 5 year old GK can handle x39, and tiny malnourished third-world teen-agers seem to have no problem with x39 so I would guess that the current crop of American kids, that average 10# bigger than we did during VN, would easily handle something stiffer than that.

7x57 Mauser recoil feels like 50% to 75% more than 7.62x39 – part of that could be the difference from semi-auto to bolt gun. I’ve never shot this Pedersen cartridge, but I’d guess recoil would be similar to the 7x57 Mauser. .308 recoil is easily 2X as stout as the x39; maybe 3X. 300WM feels about 2X again above 308. Which of your scales does that match? Maybe felt recoil is not a constant ratio to either energy nor momentum.

I love my Garand, but I’ve often thought the most awesome rifle would be a 2/3 scale Garand at about 5 pound weight, and shooting something equal to a 7mm Mauser. It would be an awesome deer rifle. An 18” SS barrel, synthetic stock, aluminum trigger group with SS face on the hammer for durability, over sized bolt lugs like an AK47, and maybe an anodized aluminum receiver since the oversized lugs would reduce the stress. I personally like that there isn’t a huge magazine sticking out the bottom of the Garand, because I can shoot off a log without the thing sticking up a foot in the air. My scoped M14 is way-dmmm tall – and heavy.

.243 Win or 250 Savage would also be fine choices for chambering a 2/3 scale Garand, and would also be adequate for shooting most critters.

...but back to the thread topic. My feeling is the answer would be no - If the USA had adopted an intermediate cartridge in 1936, there would be no point in adopting the .223. I'm not a huge FAL fan and I am glad we didn't adopt the FAL, but adopting an intermediate cartridge, like the British were proposing, would have been a good thing.

 

[iamkris]

jaimeshawn -- thanks for getting us back to our regularly scheduled thread already in progress (although...what happened to jumbee's posts? some of my answers to him look ridiculous without his posts for context)

That was kind of my thought...the .276 and .280 look almost identical to the 6.8 SPC and 6.5 Grendel ballistics. It just seems that some of the thinking pendulum has swung back to where we could have been 50-60 years ago.

Then again, if it was full auto controllability the military was after, we may have ended up with the 5.56 anyway.

 

[BigG]

Full auto controllability was the main idea.

The Army's studies in the 1950s revealed

· Marksmanship was not as important as volume of fire;
· Random shots had more chance of wounding than aimed fire;
· Small arms fire was seldom effective beyond 300 meters;
· Most kills occur within 100 meters.*

These criteria became the factors that mandated the move to small caliber high velocity in 1957. The Armalite AR10 was redesigned to take what became the 223 and Colt who purchased the rights from Armalite marketed it to the government.

*From The Black Rifle

 

[Rupestris]

No.
I think the 100gr 6mm that the Navy opted to go with would have done better, then would have evolved into something along the lines of ... 6.8SPC / 6.5 Grendel maybe.

 

[JShirley]

Random shots had more chance of wounding than aimed fire

Maybe you could restate this? One could think randomly firing your weapon- hell, at random intervals, why not- would be more effective than shooting at the enemy, and I doubt that's what you actually mean.

 

[BigG]

Maybe you could restate this? One could think randomly firing your weapon- hell, at random intervals, why not- would be more effective than shooting at the enemy, and I doubt that's what you actually mean.

That's right out of the ARMY ORO report, verbatim.

 

[artherd]

We'd probally have gone straight to a .17cal cartridge!

 

[Vern Humphrey]

John Kennedy would have nominated Robert MacNamara as Sec Def anyway -- and MacNamara would have forced the M16 on the Army anyway.

 

[3rdpig]

Yes, we'd still have created the 5.56 or something similar. The logic behind it would still be valid even if we had had the so called intermediate cartridge like the .276. For the average grunt, a lighter rifle, shooting a lighter round, carrying more of it, makes sense. Note that the Russians moved in that direction also, and we're moving further in that direction with designs like the XM8. And yes, I know the XM8 now seems dead for military service, but the logic in "lighter, smaller, more of it" is still considered to be valid.

 

[Tony Williams]

Personally, my calibrated shoulder says .223 recoil is nearly nothing. 7.62x39 recoil feels about twice that...308 recoil is easily 2X as stout as the x39; maybe 3X...Which of your scales does that match?

The energy scale. That shows that (in guns of the same weight and type - a most important qualification) the 7.62x39 develops about double the recoil of the 5.56mm, the 7.62x51 at least four times as much.

Of course, for any given cartridge, if you halve the weight of the gun you will double its recoil velocity and thereby quadruple its recoil energy.

Tony Williams: Military gun and ammunition website and discussion forum

 

[Jaws]

The answer to the original question is No.
A 6-7mm bullet out of a 40-50mm case won't have any problem with recoil or controllability in automatic firing, while maintaining good balistics.
Just look at those pictures from Africa. Look at those 50 kilos, 12-15 years old "child soldiers" shoot the ak 47. I doubt a well fed 18-19 years old American soldier would have any problem using one of those in full auto.
Is clear that something around 6.3-6.8mm is ideal for an auto carbine.

We will get to that sooner or later. If US would have to fight a war to defend their homeland and soldiers would have to drop that bad guy before he gets to kill their family, nobody would argue the need for a better round then 5.56mm.
I consider the 5.56mm NATO now exactly in the position of the .50 cal as fighter aircraft armament at the end of WW2 and the short 75mm gun on Sherman before Overlord.

Kept in place by rigidity, politics and logistics and not enough men died because of it yet.

 

[Dr. Tad Hussein Winslow]

No, had we gone there we would not have the .223 today.

+1, that's what I think, too.